A Multi-dimensional Analysis of the Open Clusters NGC 2423 and NGC 2482 with Gaia DR3

Abstract

We present a homogeneous photometric, astrometric, and kinematic study of the Hyades-like open clusters NGC 2423 and NGC 2482 based on Gaia DR3 data. Cluster memberships are determined using the UPMASK algorithm in the multi-dimensional parameter space of (alpha, delta, parallax, mu_alpha cos(delta), mu_delta), with radial velocities incorporated when available. Gaussian modelling of the astrometric distributions yields mean trigonometric parallaxes of 1.060 +/- 0.035 mas and 0.735 +/- 0.061 mas, corresponding to astrometric distances of 944 +/- 31 pc and 1361 +/- 113 pc for NGC 2423 and NGC 2482, respectively. Fundamental parameters are derived through PARSEC isochrone fitting, resulting in ages of 1250 +/- 100 Myr and 445 +/- 50 Myr, observed distance moduli (m-M)_obs = 9.90 +/- 0.10 and 10.80 +/- 0.20 mag, and reddening values E(G_BP-G_RP) = 0.07 +/- 0.01 and 0.10 +/- 0.02 mag, equivalent to E(B-V) = 0.054 and 0.078. The corresponding photometric distances are 892 +/- 50 pc and 1311 +/- 146 pc. We further investigate the internal and global kinematics of both clusters using velocity-ellipsoid parameters, the convergent-point method, and action-angular-momentum diagnostics. The derived kinematic properties show that NGC 2482 closely matches the velocity-space characteristics of the Hyades stream, while NGC 2423 shares the characteristic rotational velocity and angular momentum of the Hyades-like population but is offset in its U component. Both clusters occupy the angular-momentum range associated in the literature with Hyades-like clusters and bar-related resonances, although this association is based on their present-day kinematics and action-space locations rather than a direct dynamical demonstration of resonance trapping.